923 resultados para PAPER


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The failing heart is characterized by complex tissue remodelling involving increased cardiomyocyte death, and impairment of sarcomere function, metabolic activity, endothelial and vascular function, together with increased inflammation and interstitial fibrosis. For years, therapeutic approaches for heart failure (HF) relied on vasodilators and diuretics which relieve cardiac workload and HF symptoms. The introduction in the clinic of drugs interfering with beta-adrenergic and angiotensin signalling have ameliorated survival by interfering with the intimate mechanism of cardiac compensation. Current therapy, though, still has a limited capacity to restore muscle function fully, and the development of novel therapeutic targets is still an important medical need. Recent progress in understanding the molecular basis of myocardial dysfunction in HF is paving the way for development of new treatments capable of restoring muscle function and targeting specific pathological subsets of LV dysfunction. These include potentiating cardiomyocyte contractility, increasing cardiomyocyte survival and adaptive hypertrophy, increasing oxygen and nutrition supply by sustaining vessel formation, and reducing ventricular stiffness by favourable extracellular matrix remodelling. Here, we consider drugs such as omecamtiv mecarbil, nitroxyl donors, cyclosporin A, SERCA2a (sarcoplasmic/endoplasmic Ca(2 +) ATPase 2a), neuregulin, and bromocriptine, all of which are currently in clinical trials as potential HF therapies, and discuss novel molecular targets with potential therapeutic impact that are in the pre-clinical phases of investigation. Finally, we consider conceptual changes in basic science approaches to improve their translation into successful clinical applications.

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In recent years an increasing number of papers have employed meta-analysis to integrate effect sizes of researchers’ own series of studies within a single paper (“internal meta-analysis”). Although this approach has the obvious advantage of obtaining narrower confidence intervals, we show that it could inadvertently inflate false-positive rates if researchers are motivated to use internal meta-analysis in order to obtain a significant overall effect. Specifically, if one decides whether to stop or continue a further replication experiment depending on the significance of the results in an internal meta-analysis, false-positive rates would increase beyond the nominal level. We conducted a set of Monte-Carlo simulations to demonstrate our argument, and provided a literature review to gauge awareness and prevalence of this issue. Furthermore, we made several recommendations when using internal meta-analysis to make a judgment on statistical significance.

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Stings by Polistes wasps can cause life-threatening allergic reactions, pain and inflammation. We examined the changes in microvascular permeability and neutrophil influx caused by the venom of Polistes lanio a paper wasp found in southeastern Brazil. The intradermal injection of wasp venom caused long-lasting paw oedema and dose-dependently increased microvascular permeability in mouse dorsal skin. SR140333, an NK(1) receptor antagonist, markedly inhibited the response, but the NK(2) receptor antagonist SR48968 was ineffective. The oedema was reduced in capsaicin-treated rats, indicating a direct activation of sensory fibres. Dialysis of the venom partially reduced the oedema and the remaining response was further inhibited by SR140333. Mass spectrometric analysis of the venom revealed two peptides (QPPTPPEHRFPGLM and ASEPTALGLPRIFPGLM) with sequence similarities to the C-terminal region of tachykinin-like peptides found in Phoneutria nigniventer spider venom and vertebrates. Wasp venom failed to release histamine from mast cells in vitro and spectrofluorometric assay of the venom revealed a negligible content of histamine in the usual dose of P.l. lanio venom (1 nmol of histamine/7 mu g of venom)that was removed by dialysis. The histamine H(1) receptor antagonist pyrilamine, but not bradykinin B(1) or B(2) receptor antagonists, inhibited venom-induced oedema. In conclusion, P. l. lanio venom induces potent oedema and increases vascular permeability in mice, primarily through activation of tachykinin NK(1) receptors by substance P released from sensory C fibres, which in turn releases histamine from dermal mast cells. This is the first description of a neurovascular mechanism for P. l. lanio venom-mediated inflammation. The extent to which the two tachykinin-like peptides identified here contribute to this neurogenic inflammatory response remains to be elucidated. (c) 2008 Elsevier Ltd. All rights reserved.

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The growth of molds on paper containing cellulose is a frequent occurrence when the level of relative air humidity is high or when books become wet due to water leaks in libraries. The aim of this study is to differentiate the bioreceptivity of different types of book paper for different fungi. Laboratory tests were performed with strains of Aspergillus niger, Cladosporium sp., Chaetomium globosum and Trichoderma harzianum isolated from books. Four paper types were evaluated: couche Men (offset), recycled and a reference paper containing only cellulose. The tests were carried out in chambers with relative air humidity of 95% and 100%. Mold growth was greatest in the tests at 100% relative humidity. Results of stereoscopic microscopy observation showed that Cladosporium sp. grew in 74% of these samples, A. niger in 75%, T. harzianum in 72% and C. globosum in 60%. In the chambers with 95% air humidity Cladosporium sp. grew in only 9% of the samples, A. niger in 1%, T harzianum in 3% and C globosum did not grow in any sample. The most bioreceptive paper was couche and the least receptive was recycled paper. The composition of the recycled paper, however, varies depending on the types of waste materials used to make it. (C) 2011 Elsevier Ltd. All rights reserved.

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An important production programming problem arises in paper industries coupling multiple machine scheduling with cutting stocks. Concerning machine scheduling: how can the production of the quantity of large rolls of paper of different types be determined. These rolls are cut to meet demand of items. Scheduling that minimizes setups and production costs may produce rolls which may increase waste in the cutting process. On the other hand, the best number of rolls in the point of view of minimizing waste may lead to high setup costs. In this paper, coupled modeling and heuristic methods are proposed. Computational experiments are presented.

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It is very common in mathematics to construct surfaces by identifying the sides of a polygon together in pairs: For example, identifying opposite sides of a square yields a torus. In this article the construction is considered in the case where infinitely many pairs of segments around the boundary of the polygon are identified. The topological, metric, and complex structures of the resulting surfaces are discussed: In particular, a condition is given under which the surface has a global complex structure (i.e., is a Riemann surface). In this case, a modulus of continuity for a uniformizing map is given. The motivation for considering this construction comes from dynamical systems theory: If the modulus of continuity is uniform across a family of such constructions, each with an iteration defined on it, then it is possible to take limits in the family and hence to complete it. Such an application is briefly discussed.

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This article describes a prototype system for quantifying bioassays and for exchanging the results of the assays digitally with physicians located off-site. The system uses paper-based microfluidic devices for running multiple assays simultaneously, camera phones or portable scanners for digitizing the intensity of color associated with each colorimetric assay, and established communications infrastructure for transferring the digital information from the assay site to an off-site laboratory for analysis by a trained medical professional; the diagnosis then can be returned directly to the healthcare provider in the field. The microfluidic devices were fabricated in paper using photolithography and were functionalized with reagents for colorimetric assays. The results of the assays were quantified by comparing the intensities of the color developed in each assay with those of calibration curves. An example of this system quantified clinically relevant concentrations of glucose and protein in artificial urine. The combination of patterned paper, a portable method for obtaining digital images, and a method for exchanging results of the assays with off-site diagnosticians offers new opportunities for inexpensive monitoring of health, especially in situations that require physicians to travel to patients (e.g., in the developing world, in emergency management, and during field operations by the military) to obtain diagnostic information that might be obtained more effectively by less valuable personnel.

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Microfluidic paper-based analytical devices (mu PADs) are a new class of point-of-care diagnostic devices that are inexpensive, easy to use, and designed specifically for use in developing countries. (To listen to a podcast about this feature, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html.)

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Bill & Melinda Gates Foundation[51308]

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This technical note describes a detailed study on wax printing, a simple and inexpensive method for fabricating microfluidic devices in paper using a commercially available printer and hot plate. The printer prints patterns of solid wax on the surface of the paper, and the hot plate melts the wax so that it penetrates the full thickness of the paper. This process creates complete hydrophobic barriers in paper that define hydrophilic channels, fluid reservoirs, and reaction zones. The design of each device was based on a simple equation that accounts for the spreading of molten wax in paper.

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This paper describes 96- and 384-microzone plates fabricated in paper as alternatives to conventional multi-well plates fabricated in molded polymers. Paper-based plates are functionally related to plastic well plates, but they offer new capabilities. For example, paper-microzone plates are thin (similar to 180 mu m), require small volumes of sample (5 mu L per zone), and can be manufactured from inexpensive materials ($0.05 per plate). The paper-based plates are fabricated by patterning sheets of paper, using photolithography, into hydrophilic zones surrounded by hydrophobic polymeric barriers. This photolithography used an inexpensive formulation photoresist that allows rapid (similar to 15 min) prototyping of paper-based plates. These plates are compatible with conventional microplate readers for quantitative absorbance and fluorescence measurements. The limit of detection per zone loaded for fluorescence was 125 fmol for fluorescein isothiocyanate-labeled bovine serum albumin, and this level corresponds to 0.02 the quantity of analyte per well used to achieve comparable signal-to-noise in a 96-well plastic plate (using a solution of 25 nM labeled protein). The limits of detection for absorbance on paper was aproximately 50 pmol per zone for both Coomassie Brilliant Blue and Amaranth dyes; these values were 0.4 that required for the plastic plate. Demonstration of quantitative colorimetric correlations using a scanner or camera to image the zones and to measure the intensity of color, makes it possible to conduct assays without a microplate reader.

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Students in the Paper Hanging Department at the New York Trade School are shown in various stages of hanging paper. Black and white photograph.

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In offset printing, dampening solution is used to create a good balance in the process. If too much water is transferred to the paper, the sheet can change its size between the printing units, due to water absorption, and cause a problem with the colour register. This phenomenon is usually referred to as fanout. In this degree project, an investigation was made to see if the paper dimensions changed through its way in the sheet-fed printing process. The instrument Luchs Register Measuring Systems (Lynx) was used, and a method for measuring if the paper changed its dimensions with this instrument, was developed. Paper qualities with three different grammages were used, 90, 130 and 250 gsm. This investigation showed that all paper qualities changed their size with widening in the gripper edge in the range of 10 - 70 µm and in the trailing edge the increase was 10 - 130 µm. The elongations of the papers were in the range of 10- 300 µm. The papers with lowest grammage changed more than the heavier. To see if the print had been affected of the widening and elongation, print quality parameters like relative contrast, dot gain and mottle were correlated with the Lynx data from the sheets. The group of papers that gave correlations were in 130 gsm. The sheets had visual doubling and the combined standard deviation from the Lynx marks K3, K5 and K21 correlated with dot gain. When the variations increased so did the dot gain and this indicates that the doubling was due to the widening. There was also a correlation between the standard deviation from K3 and Mottle. The sheets widened with an average of 30 µm in the gripper edge and since there probably were doubling due to widening it also affected the Mottle values. What the widening depends on is hard to tell. Since widening was so small, it could be due to water absorption, papers being ironed out or maybe the sheets have been flattened out. It probably needs a more detailed investigation to find out what causes the widening. Further investigations about how print quality is affected by the register accuracy of a printing machine should include a print form with measuring areas close to the Lynx marks. The measuring areas should contain fine hairlines, negative text printed with at least two colours and some pictures to evaluate together with standard measuring should give a good knowledge about the subject.

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Four different trials of stratified three-layered fine paper, of sulphate pulp, were performed to investigate if stratified fine fraction or fibres from birch can improve the properties of a paper compared to a reference sheet. All trials had five different scenarios and each scenario was calendered with different linear load. All sheets had a grammage of 80 g/m2.In the first trial, the paper contained birch, pine and filler of calciumcarbonate (marble), and was manufactured with the pilot paper machine XPM and the stratified headbox Formator at RCF (Stora Enso Research Center in Falun). The furnish consisted of 75% birch and 25% pine.The second trial contained coated sheets with paper from trial one as the base paper. The coating slip contained calciumcarbonate and clay and the amount was approximately 10-12 g/m2.The third trial, also with birch and pine but without filler, was performed at STFI (Skogsindustrins Tekniska Forskningsinstitut in Stockholm) with the laboratory scaled paper machine StratEx and the stratified headbox AQ-vanes. The furnish consisted of 75% birch and 25% pine, except for one scenario which contained of 75% pine and 25% birch.The last trial contained fractionated pulp of birch and pine and was performed at STFI. 50% was fine fraction and 50% was coarse fraction.This test does not show any clear benefits of making stratified sheets of birch and pine when it comes to properties such as bending stiffness, tensile index and surface smoothness. The retention can be improved with birch in the surface plies. It is possible that the formation can be improved with birch in the surface plies and pine in the middle ply. It is also possible that fine fraction in the surface plies and coarse fraction in the middle ply can improve both surface smoothness and bending stiffness. The results in this test are shown with confidence intervals which points out the difficulties of analysing sheets manufactured with a pilot paper machine or a laboratory scaled paper machine.